Eugene c



Feb.A 5 1924.

1,482,868 E. c. RICHARD PISTON Filed March 29. 1922 {fia-mm' A PatentedFeb. 5, 1924.

UNITED STATES PATENTA OFFICE;

EUGENE C. RICHARD, OF FLINL,` MICHIGAN, ASSIGNOR TO GENERAL MOTORSCORPORA- TION, OF DETROIT, MICHIGAN, A CORPORATION OI" DELAWARE.

PISTON.

Application filed March 29, 1922.

To all whom t may concern.

Be it known that I, EUGENE C. RICHARD, a citizen of the United States ofAmerica, and a resident of Flint, county of Genesee, and State ofMichigan, have invented certain new and useful Improvements in Pistons,of which the following is a full, clear, concise, and exact description,such as will enable others skilled in the art to which the inventionrelates to make and use the same, reference being made therein to t-heaccompanying drawings, which form a part of this specification.

My invention relates to pistons such as are used in` single actingengines, air pumps, etc., and especially to pistonsl designed especiallyfor use in internal combination englnes.

The object of my invention is to provide means associated with a pistonfor preventing sidewise -movement thereof wit-hin the cylinder in wfhichit operates, which is a phenomenon well known to automobile engineersand one commonly referredl to as piston slap and is characterized bypounding noises when the engine is in operation; the movement being dueto complex variations in magnitude and direction of various forcesacting upon the piston, particularly in an internal combustion engine,accentuated by the looseness of the piston within its cylinder necessaryin internal combustion engine practice to avoiding seizing of the pistonwithin the cylinder under the high temperature conditions present insuch engines.

The drawing accompanying and forming a part of this specificationillustrates the preferred embodiment of my invention; although it willbe appreciated that the invention may take other specific forms, andthat the same includes all such variations and modifications of theparticular embodiment thereof illustrated and hereinafter described ascome within the scope of the concluding claims, wherein thedistinguishing features wherein my invention consists are particularlypointed out.

In the drawing:

Figure 1 is a fragmentary sectional view showing an engine cylinder withmy improved pistion therein in elevation.

Figure 2 is a View showing a section of my improved piston upon alargerscale',

Serial No. 547,724.

and upon a longitudinal plane at rightangles to the piston pin and tothe crank shaft of the engine.

Figure 3l is a view showing a section upon a transverse plane at rightangles to the path of travel of the piston and located at the pist-onpin.

Figure 4- is a fragmentary sectional similar to Fig. 3 but showing amodilied form of my invention.

Referring now to the drawing, the reference numeral 4c designates anengine cylinder, 5 the crank shaft and 6 the connecting rod of theengine, all in a conventional manner; the upper end of the connectingrod being connected with the piston 7 through and by means of atransversely extending piston pin 8 shown as hollow and the ends ofwhich are supported in bearings provided in the peripheral wall of thepiston; all as is usual in internal combustion engine practice. Thepiston will be provided with the usual packing rings 9, as many as maybe deemed necessary or desirable in each particular case.

The piston 7 is provided witha recess or groove 10 in its periphery orcylindrical portion and which groove extends circumferentially about'the piston, and is preferably so located that it extends across theopenings in the piston wall in which the ends of the piston pin 8 aresupported, and the numeral 1l designates a ring located Within thegroove and which ringis split or divided as indicated at i2.

The peripheral wall or skirt of the piston is provided with a hole at 13opening int-o the bottom of the groove, and which hole is .illustratedas arranged at approximately vninety degrees (900) to the axis of thepiston pin and at one end of a diametrical line or dimension of thepiston; and 14 designates a plunger the outer end of 'which abutsagainst the inner surface of the ring ll, andF which plunger is forcedoutward and against the ring by a spring carried by the piston-:theresult being that the piston is forced bodily sidewise and in adirection substantially at right angles to the axis of the piston pinand against the interior of the cylinder diametrically opposite theplunger 14; as the cylinder wall adjacent the point of contact betweenthe end of the plunger and the ring provides a Axed abutment view -lll

against which the spring acts, the piston as a Whole being free to move;and the same being in fam moved in the manner More said b the reactionof the spring acting throug the plunger and porton of the ring engagedby the free end thereof, against the cylinder wall which provides afixed abutment or stop for the ring.

The spring aforesaid is preferably U- shaped as shown and comprises amiddle portion l5 which is lixedly secured to the inner end of theplunger 14, and side portions 16 having large holes throuvh which thepiston pin extends; and wliereby the spring and plunger are supportedfrom the piston pin and from the hole in the piston wall throu h whichthe outer end of the plunger extends.

The action of the spring -to force the piston bodily in a direction atright angles to the axis of the piston pin will obviously occur in allcases wherein the spring is free to actagainst a relatively looseelement carried b piston, and which element is presse a ainst thecylinder Wall by the spring andV for which element the cylinder wallrovides a fixed abutment; from which it fol ows that the ring orequivalent abutment member need not of necessity be split, and need notextend throughout the entire circumference of the piston; so long as theabutment member thus provided is loose relative to lthe iston so that 1tmay be forced outward y the spring and against the adjacent inner wallof the cylinder.

The split ring shown, however, is preferable, as it may then be readilyintroduced into a groove in the iston and acts as a packing element in adition to an element against Which the end of the plunger acts in themanner and for the purpose hereinbefore explained. The location of thegroove shown secures a construction in which the ring prevents the endsof the piston pin from coming into Contact with the interior of thecylinder and scoring the same which, While not in itself a new idea, isa feature of manifest advantage secured in my invention.

The spring member of my invention instead of beine 'flat as shown inFigures 2 and r3 may be inthe form of a coiled spring t7 extendingthrough a hole 18 iu the cylinder and acting upon the inner surface ofthe abutment member 19; the inner end of the saidA spring acting`against a stirrup .20 simi lar in form to the U-shaped springhereinbefore referred to and similarly supported within the iston, butwhich) need not `be resilient as t e sprinor action is provided by thesaid sprin ll'J which obviously acts against the mem er 19 Iin reciselythe same mnner as the plungerll 1n the form of 'my invention firstherein described.

Having :thus described and explained my a U-shaped spring member thesides of which are supported by said piston pin and the middle portionof which is operativelyy connected with said plunger.

2. In comblnation with a hollow piston having a transversely extendmgpiston 1n,

a groove in its peripheral surface exten ing circumferentially thereof,and a hole aryA ranged substantially at right angles `to the axis of thepiston pinand extending through the piston Wall and into the grooveaforesaid; a lsplit ring located Within said groove; aplunger extendingthrough said y hole and engaging the inner surface of said ring; and aspring member supported by said piston pin and operatively connectedwith said plunger and actin outvvar-dly against said ring throufrh saiplunger.

3. ln combination Wii vhaving a transversely extending piston in, agroove in its peripheral surface exten ing circumferentially thereof,and a` hole arranged substantially` at right angles toy the axis of thepiston pin and extending through the piston Wall and into the grooveaforesaid; asplit ring located within said groove; a plunger extendingthrough said hole and engaging the'inner surface of said ring; and aspring member located within the piston and acting upon said plunger toforce the same outwardly against said ring.

4. In combination with a 'hollow piston `having a transversely extendingpiston pin, a groove in its peripheral surface .extendingcircumferentially thereof, and a hole extend'- ing through `the `pistonWall and into the groove aforesaid; a ring located within said groove;and spring operated means located within the piston and acting againstsaid piston pin and through said hole and against said ring. y

5. In combination with a hollow piston having a transversely extendingpiston pin, and a grooveI in .its peripheral surface; an abutment member'located in said groove; and a spring located Within said iston andacting between said piston lpin andp said abuta hollow pistonL mentmember to force said abutment against i `the interior of a cylinder inwhich the piston o erates the arrangement of the elements a' oresaidbeing such that pressure applied to said abutment member "by saidYspring reacts to force the piston bodily in a direction at right anglesto the axis of said piston pin.

6. In combination with a hollow' piston having a transversely extendingpiston pin, and a-recess in its peripheral surface; an abutment memberlocated in said recess; and a spring acting between said piston pin andsaid abutment member to force said abut-- ment against the interior of acylinder in which the piston operates; the arrangement of the elementsaforesaid being such that pressure applied to said abutment memberreacts to force the piston bodily in a direction at right angles to theaxis of said piston pin.

7. The combination with a hollow piston having a transversely extendingpiston pin, of means separate from the piston and locatn ed within thesame, and carried by the piston pin, and acting against the wall of acylinder in which the piston operates for forcing the piston bodily in adirection at right angles to the axis of the piston pin.

In testimony whereof I aiiix my signature.

EUGENE C. RICHARD.

